C21 is a new technological advanced devolved city with the purpose of establishing their corporation named D-93. With the rumours flying around about the possible upcoming deadliest war, ungifted humans have been ordered to evacuate to newly built towns.

Being pregnant with the child of the man who left her for another woman was never an easy issue to Park Shin Hye. She was disrespected in the society and even her parents rejected her. She decided to lock all doors of her heart, and handle her pregnancy all alone, but things changed when a new neighbor Oh Sehun moved into the neighborhood.

Winters are Jihye's favourite season.
Her winters were always filled with warmth.
This winter, instead of her constant warmth, all she was surrounded with was the brutal cold.
Her boyfriend, Sehun, does his best to provide her with all the warmth.

Oh Sehun is Korea's most wanted criminal for being the notorious leader of a Mafia gang. While threatened by the presence of an investigator called 'Special Agent J', Sehun finds comfort in his favourite club. More notably, the new club worker who he recently has eyes on.

Cho Haneul doesn't want to fall in love. Her reason? With love comes hurt, and witnessing the pain of love came the refusal to fall in love.
Then came Oh Sehun, a boy that seemed like a cold, rude guy at first, but became a soft hearted gentleman around her as soon as he saw her genuinity.
Can the warmth of one man change her mind

"I am devil sweetheart and you seem so innocent to fit in my world." he said with a cold smirk on his lips.
"Make me your angle then!" she retorted with same intensity.
"Who knows you maybe a devil in disguise!" he accused